1. Field of the Invention
The present invention relates to a magnetically operated or assisted power transmission apparatus and more particularly to a power transmission apparatus of the type utilizing magnetic force for making a reliable operative connection between a driving pulley and a driven pulley to steplessly transmit rotational power outputted from a prime mover to a power consuming machine or apparatus.
2. Description of the Prior Art
A hitherto known stepless power transmission apparatus of the type including a driving pulley and a driven pulley in generally constructed such that the former is designed in the form of a disc and the latter is designed in the form of a truncated cone so that rotational force outputted from the prime mover is transmitted to the power consuming side by way of frictional contact between both the driving and driven pulleys. Because of the fact that power transmission is achieved merely with the aid of frictional force in the contact area between both the pulleys, the conventional stepless power transmission apparatus has a drawback in that some slippage takes place in the contact area, resulting in reduced power transmission efficiency.